Adjustable false work.



R. A. CUMMINGS.

ADJUSTABLE FALSE WORK.

APPLICATION FILED AUG.3. 1914.

Patented Dec. 14, 1915.

2 SHEETSSHEET I WITNESSES W R. A. CUMMINGS.

ADJUSTABLE FALSE WORK.

APPLICATION FILED AUG.3, I914.

Patented Dec. 14, 1915.

2 SHEETS-SHEET 2.

INVENTOR FIG.7

Uhlliiitl} Parana @FFEQEL ROBERT AUG'UST US CUMMINGS-i, F PITTSBURGH, PENNSYLVANIA.

AnJUs'rannn r'ansn wonK.

ieaeai.

. Application fi1edaug sta191'4. jSeria11Io.854,678.

To all whom it mag/ concern:

ra 'ry support for retaining walls, or in any other manner as a temporary supporting structure.

The object of the invention is to provide improved false work of the character clescribed which is made of units so that it can be readily assembled and disassembled, which can be used'repeatedly, and which may be connected or adjusted in various ways and may be built up to any desired size or configuration so that a single set of false work is adapted for use in many different ways and in the construction of various forms of arch or other structure having spans of different lengths and curvature;

The invention comprises the construction and arrangement of parts hereinafter described and claimed.

In the drawings, Figure l is a diagrammatic view, showing the false work applied for use as centering for a concrete arch; Fig.

2 is a detail elevation thereof, showing two units of the false work or centerlng, and 1n-* dicating the lines of the arch being formed; Fig. 3 is a similar view showing another arrangement for imposing the load upon the false work and also illustrating a modification; Fig. i is a detail plan view, showing one of the hinge connections between adjacent units of the centering; Fig. 5 is a cross section on the line 55, Fig. 2; Fig. 6 is a plan view of one of the members for connecting adjacent units; Fig. 7 is a crosssection thereof on the line 77, Fig. 6 ;v Fig. 8

is a diagrammatic view of another form of centering; and 9 is a similar View, illustrating a further modification.

Referring to the drawings, Fig. 1* illustrates the invention applied for use ascentering for supporting the arch of a concrete bridge durlng the course of erection there- Speeificaticn of Letters Patent. P te t u le, 1915,]

of. Thebridge comprises the usual piers 1 I and an arch 2, the intrados curve of which is marked 3. Suitable, means is provided for supporting the centering, such as shown at I 4, Fig. 2, which support carries a number of cross beams 5,'upon-which are superposed the shoes 6 for supporting the ends of the.

centering. Preferably, suitable anti-friction members, such as the rollers 7, are interposed between the shoes and the cross beams 5, in order that thecenterlng may be adjusted laterally underneath different por tions of the arch being formed.

The centering comprises two or more trusses 8 lying parallel with each other and I extending across the span and connecteditogeth er by suitable lattice work consisting of cross members 9 and diagonal members 10,

so that when assembled they act as one member and may be handled together.

The false work comprises a suitable number of identical units 11, which may be of any shape, but preferably are triangular units, as shown in'Figs. 1 and 2. The end units are pivotally connected,as at 12 to the shoes 6. Each unit comprises an outer or upper member 13, and two other members 14, which are connected at their ends in order to form substantially an equilateral triangle. Each outer member 13 is shown as formed of two channels 15 placed web to web and at their ends having gusset plates 16 interposed between their webs. Pin plates 17. are also placed on the outside of the channels at each end, the whole being riveted together in order'to make a solid, rigid beam. The pin and gusset plates project from the ends of the beams and are pierced to receive the hinge pins 18 for pivotally connecting adjacent units of the false work along its extrados side to each other. The pin and gusset plates, of which there are three at the end of each beam, therefore form hinge leaves, lying in staggered relation to each other, so that the strain is distributed along the length of the hinge pin and decreases the liability of failure in on opposite sides of the gusset plates 19,

shear. The other two members let of each unit may be of any suitable section, such as angles, and are connected at one end to the gusset plates 1% and at their other ends to a third gusset plate 19.

The hinge connectlons between adjacent. units'all lie along theextrados side of the false work, but the several units are also connected along the intrados side of the false work,-and preferably in such-manner that tl16f1 6l&t10l1S"0 the several units to each other may be varied m order to. adapt the false work for any particular use, that is, as

centering for different shapes of arch, or as a temporary supporting structure of any kind. In the form shown inhig. 2' the ad- ,jacent units are connected by members 20,

shown as formed of two parallel wooden members 21 of rectangular cross section and rigidly connected atftheir ends in any suitable manner, as by angles 22. Two plates extend endwise from said members and lie to which they are connected by hinge pintles 28. The connecting members 20 are also provided with longitudinal tie rods 24:, which are, provided with nuts for tightening them up. The connecting members 20' are preferably made of wood in order to enable them toresist compression strains, and are provided with tie rods in order that they may resist tension, as these members are subjected toboth kinds of stresses during the course of erection of the false work and its final useas a temporary supporting structure. V 7

Several sets of connecting bars 20 may be 7 provided for-use with each set of false work or said connecting bars'may be; made of various lengths upon the ground by insert- *ing wooden bars 21 of the proper length.

This is done in order that the relations of the units to each other may be varied. the connectingbars 20 are of the same length as the upper and outer bars 13 the temporary false work is straight, that is, its ex-- trados and intrados sides are straightlines, as shown in Fig. 9. If the false work isto be used as centering for supporting an arch, as in Fig. 1, the connecting bars 20 are made shorter than the outer members 13 of the eXtrados side of the false work, which gives the extrados side of the false work a curve whose amount of curvature may be varied by varying the lengths of different connecting members 20 on the intrados side of the false work. As the curvature increases the connecting members 20 are shortened, while if the arch to be formed has a flatter curve the connecting membersQO are lengthened.

The members for connecting the apices of adjacent units of the false Work may also be made adjustable if desired, in order to save the necessityof providing sets of'members ofdifferent lengths. example, Fig. 3

shows a connecting member 25 provided with eyes 26 at its oppositeendsfor receive ing the hinge pintles27,said member being also provided, intermediate its ends, with suitable means, such asan adjustable turn buckle-28, whereby its length may be varied. Such a member is useful in cases where substantially not compression strains are to be imposed upon the lower members of the.

false work, as they are effective only to resist tensile strains.

The centering 'orfalse work may be built up of any desired number-of ui1its,depending upon the characteristics of the structure with which it is to be used, such as the length of the span and the curvature of the in By placing'the trados. side of the arch. shoes 6 at the proper point, selecting the proper number of'units, and choosing mem-' bers of theproper length for connecting the units along the intrados side of the false work, the latter may be adj usted to conform fairly. closely to almost any curvature of arch.

. The load may be imposed upon the' false work in any suitable manner, either concenv trated upon the several pivots connecting adjacent units of the false work, or distributed along the ,outer and upper members thereof. In 2 the lagging 29 which formsthe floor for receiving the concrete of the bridge rests upon'longitudinal risers 30,,

closely adjacent to their ends. In this case the load is practically concentrated at the pivots connecting adjacent members or units of the false work, and the outer members 13 of the false work consequently are subjected substantially only to compression.

The outer members 13 of the false work practically carry the entire weight of the arch during the course oferection, as little dependence is placed upon the angle members l t and connecting; members 20 for support. They merely hold, the'outer members 13 in the proper positions to gi-ve the arch being formed the proper curvature along its intrados side; In fact, the member which connects the two units on each side of the crown of the arch, and marked 20 in Fig. 1, may be wholly omitted, if desired, although preferably none of the connecting members 1 are omitted andthere is a continuous chain weasel work. 7

Fig.8 shows jainodified form of the ventionin which the false work consistsof a number of four-slded units 35. The outer membersSG of said units which carry the lagging for supporting; the-arch to .be

of the centering are also connected by two sets of cross members, marked respectively 40 and ll, and which members are connected at their ends 3721116139. The membersBS, a0 and 38 are .all of uniform length. The members 41 extend diagonally across the several units, being inclined upwardly and away from the center of the arch in order to take tension strains. adjusted. to conform to any desired curvature by lengthening or shortening the diagonal members il, which are provided with suitable ad'ustin means such as the turnbuckles for that purpose. By varying the length of the diagonal members l1 the several units are made more or less diamondshaped, which varies the relations of the adjacent outer members 36 to each other. In this case, also, the two end units, marked 4:3, are rigid and triangular in shape, so that the complete false work is substantially crescent shaped.

l/Vith all forms of false work or centering described the several units are made of a size depending upon the size of the structure to be produced. Preferably, a large number of units is used, so that if one side of the false work is to be curved, as when the false work is used as centering for an arch, the extrados curve of the false work consists of a large number of short, straight lines, and the more units that are used the nearer does the false work conform to the actual curvature of the arch. Preferably, the units at opposite ends of the false work are connected by a tie bar ll), the opposite ends of which are connected to the pivots or gusset plates at the apices of the end units. This tie bar is preferably provided with suitable means for adjusting its, length, such as the turn buckles 46. In striking the centering the wedges are withdrawn from between the false work and the arch which has been formed, and at the same time the turn buckles 46 in the bars 45 are tightened up. These bars consequently relieve the centering from strain andform supports therefor while striking centers. They also form supports for the centering when the latter is moved laterally across the bridge to a position for forming the next rib thereof.

The false work described is simple and is thereofalong the intrados side of-the false This false work is P readily manufactured from ordinary structural steel shapes, although anyfsuitablema-j terialsrnay be usedtherefor. In practice i I is foundthat one ortwo sets o flsu'ch false work will serve for almost all forms of temporary .supportinjg;structures. It may be used for temporary foot bridges, for tein-J' porary supports for vertical retaining walls, or for the erect on farchesof any des gn and size, such as the arches of sewers, aqueducts, bridges and the like.

lVhat I claim'is 1. A temporary supporting structure, comprising two rows of longitudinal memconnecting the endsfof the longitudinal members of said rows and thereby forming a series of successively disposed triangles,

and; hinge connections between successive bers, and a series of transverse members longitudinal members, some of the members i of said" triangles being variable in length to thereby permit the relations between succes sire longitudinal members to be varied to thereby vary the curvature of the structure.

2. A temporary supporting structure, comprising a plurality of like triangular units hinged together at their corners with a side of each unit lying on one side of the structure and its other two sides forming diagonal transverse members, anda set of members connecting the corners of said triangular units where the diagonals of each unit converge, said connecting members being variable in length, whereby the relations of the units to'each other may be varied and bending strains on the transverse members are avoided.

3. A temporary supporting structure, comprising a plurality of like units, each unit comprising a plurality of members lying in parallel planes,,cr0ss and diagonal braces connecting said members, hinge connections between said units along one side of the structure, and adjustable'connections between the units along the otherside of the structure. 7 7

4. A temporary supporting structure, comprising a plurality of like units hinged together at their corners with a side of eachunit lying on a side of'the structure and the other two sides forming diagonal transverse comprising a plurality of like triangular units, each unit, comprising rolled steel members, gusset plates connecting said members V I -1 ,-163,'64i

attl ieldri irs 0f the triangles, sziid mmln testil ionywhereof, I have hereuntd set bers being hinged together along oneside of my hand. the structure, and each unit havmg a corner 0n the other side ofthe structure, andyad- ROBEM AUGUSTUS CUMMINGS I 5 justable members connecting the gusset WVitnesses: v plates at the corners of achacent' units on 1 GLENN H. LEREscHE,

the other side df the structure, v v ELBERT L. HYDE.

Copies of this patent majbe obtained for five cents each,-by addressing th Commissionrof Patents. 7' Y r .Washington,D.O. 

